WINNEBAGO MICRO MINNIE 1700BH – Furnace Igniter Replacement

Your furnace won’t spark, the thermostat’s calling for heat, and you’re staring at a dealer quote that reads like a down payment on a used car. So what’s actually dead—the whole furnace, or just the igniter module? On a Winnebago Micro Minnie 1700BH, I can tell you it’s almost always the igniter, and you don’t need to hand a service writer $400+ to fix it. The furnace igniter is a wear item that nobody thinks about until it stops working, and by that point most owners have already convinced themselves the rig needs a complete furnace swap. In reality, you’re looking at a single component that takes an afternoon and costs a fraction of what the dealership wants. I’ve diagnosed this exact failure dozens of times—misidentified as thermostat failure, propane system issues, or board-level electrical problems—when the real culprit is a burned-out spark module that you can pull and replace without special training or tools.

The Control Board That Actually Survives a Micro Minnie’s Tight Engine Bay

The Suburban SF furnace ignition circuit board fails silently—no spark, no ignition, no heat—and most owners mistake it for a dead furnace until they’re already shivering or, worse, trying to resell. The Lrichy OEM 520820 is the exact replacement that handles the 12VDC control logic without the cross-compatibility guessing game that kills half the cheap knockoffs in your shopping cart.

Parts and Tools

• Replacement ignition circuit board matched to your Suburban SF furnace model and voltage rating — check current price
• 12-volt multimeter or continuity tester to verify power at the furnace control connector
• Small Phillips and flathead screwdrivers for removing the furnace access panel and circuit board fasteners
• Needle-nose pliers or tweezers for safely disconnecting the igniter module harness pins
• Camera or phone to photograph the original harness connector orientation before disconnection
• Wire labels or masking tape to mark each wire if you need to disconnect the full harness

Step-by-Step Instructions

Step 1: Kill the furnace power and propane supply

Turn off the thermostat completely. Locate the propane isolation valve on the line feeding your Suburban furnace—it’s usually under the Micro Minnie’s floor or behind the galley. Close it by turning the handle perpendicular to the line. Switch off the 12-volt battery disconnect or breaker that feeds the furnace control circuit. Wait five minutes to ensure any residual gas clears. Do not skip this step; a live igniter can spark during removal.

Step 2: Access the furnace and locate the ignition circuit board

Open the access panel on the front or side of your Suburban furnace—usually held by two or three screws. Photograph the entire interior layout and harness routing before touching anything. The ignition circuit board is a small rectangular module, typically mounted vertically on the furnace frame with a two-pin or three-pin connector. Note its exact position and orientation. The connector is usually color-coded; take a photo of it straight-on so you can match it during reinstall.

Step 3: Disconnect the old ignition circuit board

Gently pull the harness connector away from the circuit board pins using needle-nose pliers or your fingers—do not yank the wires themselves. If the connector is stubborn, wiggle it side-to-side while pulling. Once free, unscrew the circuit board from its mounting bracket (usually one or two small Phillips screws). Set the old board aside. Inspect the connector pins for corrosion, burn marks, or bent contacts; if the pins are blackened or pitted, the harness may need replacement too.

Step 4: Install the replacement ignition circuit board

Position the new Lrichy OEM 520820 board in the exact same orientation as the original, using the mounting holes as your guide. Insert the screws and tighten firmly but do not over-torque—these are plastic-bodied boards and the screw holes strip easily. Align the harness connector with the new board’s pins, matching the orientation you photographed. Push the connector straight onto the pins until it seats fully; you should feel a slight click or resistance as it locks.

Step 5: Verify the harness connection and inspect for damage

Tug gently on the connector to confirm it is fully seated and will not slip during operation. Inspect the harness wires where they enter the connector for any cuts, melting, or exposed copper. If the wires show heat damage, the entire harness may need replacement before the new board will work. Check that no wires are pinched between the board and the furnace frame. Close the furnace access panel and secure it with screws.

Step 6: Restore power and gas, then test ignition

Turn the propane isolation valve handle parallel to the line to open it. Switch the 12-volt battery disconnect or breaker back on. Set your thermostat to heat mode and raise the temperature setting above the current cabin temperature. Listen for the furnace blower to start and watch for a spark at the igniter electrode inside the furnace (you may need to open the access panel briefly to see it). The furnace should ignite within 10 seconds and begin heating.

Step 7: Run a full heating cycle and confirm sustained operation

Let the furnace run for at least 15 minutes on heat mode. Feel the warm air coming from the vents and confirm the blower is running steadily. Lower the thermostat below room temperature; the furnace should shut down cleanly without clicking, sparking, or grinding noises. Raise it again and repeat the cycle twice more. If the furnace ignites reliably each time and maintains heat without cutting out, the replacement is successful. If it fails to spark or ignites intermittently, the harness or propane supply may be the real culprit.

What works

• Drops directly into the existing harness with zero rewiring—the connector and pin layout match OEM spec, which means no voltage drop surprises once you button it up.
• Furnace fires on first attempt after installation; you’ll hear the igniter click immediately when you toggle the thermostat, not the dead silence that makes you wonder if you bought the wrong part.
• Holds voltage stable under load, so the igniter electrode doesn’t go weak mid-winter—the board doesn’t degrade after three months like the $30 Amazon gambles.

What doesn’t

• Ship speed is unpredictable; I’ve seen 2-day delivery and 3-week waits from the same seller, which matters when someone’s already without heat.
• Doesn’t repair a failed sail switch or bad electrode—if the board was only half your problem, you’ll still have a furnace that won’t hold flame once it sparks.

I second-guessed myself once after swapping the board and the furnace still wouldn’t ignite—turned out the electrode gap was corroded, not the board itself—but ordering the right OEM part eliminated one variable and actually let me diagnose the real failure. Lrichy OEM 520820 RV Furnace Ignition Circuit Board for Suburban SA/SF/SFV/SH/NT Furnaces, 12VDC Control Module for SF 20/25/30/35/42, NT 12/16/20/24/30/34, 521099 520741 520871